Drum support and drive system for reproduction machines



Sept. 24, 1968 H. TURNER 3,402,660

DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES Filed Sept. 30, 1965 15 Sheets-Sheet l INVENTOR. LYMAN H.TURNER L. H. TURNER Sept. 24, 1968 DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES 15 Sheets-Sheet 2 Filed Sept. 30, 1965 LYMAN H. TURNER y zb Sept. 24, 1968 H. TURNER 3,402,660

DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES Filed Sept. 30, 1965 13 Sheets-Sheet 5 INVENTOR.

FIG. 4 LYMAN H.TURNER /ff 1 a ATTORN Y L. H. TURNER Sept. 24, 1968 DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES l3 Sheets-Sheet 4 Filed Sept. 30, 1965 INVENTOR. LYMAN H. TURNER BY )4 Sept. 24, 1968 L. H. TURNER 3,402,650

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74 7o I a INVENTOR. LYMAN H. TURNER ATTORNEYS Sept. 24, 1968 H. TURNER 3,402,660

DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES Filed Sept. 30, 1965 M 16 Sheets-Sheet '7 INVENTOR. LYMAN H.TURNER TTORNEYS v H. TURNER 3,402,660

DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES Sept. 24, 1968 13 Sheets-Sheet 8 Filed Sept. 30, 1965 FIG. /4

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DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES Filed Sept. 30, 1965 l3 Sheets-Sheet 11 e -"nn l u INVENTOR. LYMAN H. TURNER BY%/m L. H. TURNER Sept. 24, 1968 DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES l5 Sheets-Sheet 12 Filed Sept. 30, 1965 INVENT OR. LYMAN H. TURNER BY z Sept. 24, 1968 T R 3,402,660

DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES Filed Sept. 30, 1965 13 Sheets-Sheet 15 FIG. 25

INVENTOR. LYMAN H. TURNER ATTORNEYS United States Patent 3,402,660 DRUM SUPPORT AND DRIVE SYSTEM FOR REPRODUCTION MACHINES Lyman H. Turner, Pittsford, N.Y., assignor to Xerox Corporation, Rochester, N.Y., a corporation of New York Filed Sept. 30, 1955, Ser. No. 491,556 4 Claims. (Cl. 101-132) ABSTRACT OF THE DISCLOSURE The present invention relates to reproduction machines and more particularly to an arrangement for supporting and driving a drum and roller in a reproduction machine.

Generally, reproduction machines of the pressure-transfer configuration, which is particularly suitable as an environment for the present invention, are of two broad types. One type, known as a spirit duplicator, requires a copying fluid or spirit which moistens each copy sheet as it passes between a rotatable platen which supports a master or transfer sheet and a pressure roller. The spirit dissolves some of the dye on the master sheet, and the resultant dissolved dyestutf is transferred to the copy sheet as it is transported between the rollers.

Another type of pressure-transfer duplicating equipment combines the effect of heat and pressure to effect transfer from a transfer sheet to a copy sheet. This type of equipment may take various forms and material such as the use of fixing compositions for the dyes imprinted upon a master sheet wherein heat is utilized to cause or enhance reaction between the dye and the fixing composition. Special circuits and temperature control devices are provided in these duplicating machines for insuring optimum transfer conditions.

Significantly, the present invention takes on added importance in that it may be devised for use in a reproduction machine having a compact size, requiring a minimum of operative steps, and which may be quickly brought into operation by the mere push of a button. With these advantages, the machine incorporating the invention is particularly useful as a companion machine to the conventional typewriter, to 'be made a part of or an adjacent neighbor thereto and serve to eliminate the need to make carbon copies by use of the typewriter. In fact, the machine incorporating the present invention derives its most useful benefit in that duplication of a typed original document may be accomplished solely by the machine, thus eliminating the cumbersome application of carbon paper to the typewriter and the burdensome manipulation of the carbon sheets in order to effect erasures of the carbon sheets and corrections to the original.

It is a principal object of the present invention to improve oflice duplicating machines for general copying use by utilizing a roller support arrangement at both ends of a copy drum and a cooperating roller between which copy sheets are driven for the transfer of images.

Another object of the invention is to utilize a plurality of roller bearings for supporting both ends of a copy drum thus eliminating the need for cumbersome supports. Still another object of the invention is to reduce the size of office duplicating machines by providing a roller bearing support arrangement at both ends of a copy drum thereby permitting the mounting of a drive motor wholly within the drum.

In order to accomplish these and other objects of the invention, there is provided a roller bearing support and drive mechanism in a duplicating machine of the type which operates under a dry process requiring merely the application of pressure in order to effect transfer of information on an original document to ordinary copy paper. Any other suitable reproduction machine may be utilized to practice the present invention. The duplicating machine that will be described in association with the present invention comprises a rotatable drum for supporting therearound a transfer sheet and for moving first an original document therewith and then a sheet of copy paper. A roller is also provided and is arranged to be in pressure contact with the drum by means of a toggle-joint force producing mechanism for effecting ink transfer. Each revolution of the drum is adapted to complete one reproduction of the original document, and a counter mechanism is set into motion in cooperation with a programmer device in order to register individual copies being produced. There are included in the machine guide means and registering means for insuring accurate feeding and movement of the various sheets into and through the machine, and paper clamping devices, under control of the programmer device, for controlling the movement or release of the sheets.

Further objects and advantages will become apparent after reading the following description when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is an isometric view of the reproduction machine which embodies the present invention;

FIG. 2 is a front elevational view of the machine partly in section with other parts broken away;

FIG. 3 is a sectional view of the machine taken along the line 3-3 in FIG. 2 and showing a force generating mechanism utilized for exerting pressure between the copy drum and the pressure roller;

FIG. 4 is a schematic view of the drum and pressure roller in peripheral contact to emphasize the crowned configuration of the roller;

FIG. 5 is a left-hand end View of the machine in FIG. 1 showing the drive mechanism utilized therein;

FIG. 6 is a cross-sectional view of the copy drum taken along a vertical plane parallel with the axis of the drum and showing the drive mechanism for the roller and the drum and the sheet material grippers;

FIG. 7 is a schematic illustration combined with a force diagram of the force generating mechanism;

FIG. 8 is a cross-sectional view taken along the line 8-8 in FIG. 2;

FIG. 9 is an enlarged sectional view of a detail taken along the line 99 in FIG. 8;

FIG. 10 is an enlarged sectional view of another detail;

FIG. 11 is an enlarged view of one of the registration devices utilized in the present invention;

FIG. 12 is a sectional view taken along the line 12-12 in FIG. 11;

FIG. 13 is an enlarged view of one of the clamping mechanisms utilized in the present invention;

FIG. 14 is a sectional view taken along the line 14-14 in FIG. 13;

FIG. 15 is a schematic illustration of the relationship of transfer material and structure used in cooperation therewith;

FIG. 16 is an enlarged fragmentary view of a detail of the invention in one position of operation;

FIG. 17 is an enlarged fragmentary view of the detail in FIG. 14 in a position of operation;

FIG. 18 is an enlarged fragmentary view of the detail in FIG. 16 in another position of operation;

FIG. 19 is a plan view of the programmer mechanism utilized in the reproduction machine;

FIG. is a side elevational view of the programmer mechanism;

FIGS. 21, 22, 23 and 24 are schematic views of portions of the programmer mechanism shown in other positions of operation; and

FIG. is an electrical diagram utilized in the disclosed reproduction machine.

The duplicating machine to be described herein is particularly adapted for printing out copies on ordinary copy paper by means of a pressure transfer process involving a master or transfer sheet material produced as the first operative step in the use of the duplicating machine or of any particular run of the machine. The master or transfer sheet, in turn, derives or acquires the information to be reproduced from an original produced independently of the duplicating machine, such for example, by typing with a conventional typewriter.

In order to devise a transfer sheet that is usable with the present machine, the ink or pigment presented upon the transfer sheet must be transferable by the application of relatively high pressure. Production of the transfer sheet may be accomplished by two methods:

(a) The direct method wherein the transfer sheet is typed along with the original and a sheet of special carbon paper is positioned behind the transfer sheet with the carbon ink facing the master, and

(b) The indirect method wherein the informational image is formed by typing with a special typing ribbon onto the original from which the image is transferred to a transfer sheet under pressure. The present duplication machine is adapted to accommodate a transfer sheet produced by either method; however, it is preferred that the indirect method be employed since this method would not involve the added manipulative steps with a typewriter, that is, arranging an original, a carbon sheet and transfer sheet material in a typewriter and insuring adequate alignment of these sheets relative to one another. Essentially, the indirect method involves single-sheet typing.

In the direct method, the master sheet is generally made of wax paper which may be wax coated base stock paper, whereas in the direct method, the transfer sheet need not be wax coated. The ink formulation for either the ribbon in the indirect method or the carbon paper in the direct method may include a small percentage of wax; a large percentage of pigment, usually iron oxide or carbon pigment; and a modifier, such as petroleum and chlorinated rubber, which serves as a binder.

In producing a transfer sheet by the indirect method, the ink from the typewriter ribbon is transferred to the original sheet by the striking of each typewriter key, as is the case with single copy typing. The typed original is usable as such and may be mailed or routinely handled as an ordinary type ribbon copy. Reproductions of the origi nal can be made by means of the present machine in view of the fact that a portion of the ink on the original will be transferred to the transfer sheet materials by the application of pressure. To reproduce copies, the original sheet and a transfer sheet are aligned in the feed tray with the typed copy in contact with the coated surface of the transfer sheet and fed into the machine incorporating the present invention wherein high pressure is applied as the sheets are rolled through the pressure area in the machine. This action transfers the ink from the original to the transfer sheet. The transfer sheet is retained in the machine while the original is fed out. To make copies, a sheet of ordinary copy paper is placed in the feed tray where it is automatically registered with the copy on the transfer sheet and then rolled through the pressure area of the machine. With the application of pressure, some of the ink is transferred from the transfer sheet to the copy sheet. This step may be repeated in order to produce any number of copy sheets, for example, ten copies or more, depending upon the ink depth and the porosity of the papers utilized.

Referring to FIGS. 1 and 2, the duplicating machine embodying the present invention includes a drum 10 mounted for rotation on a base casting 11 having vertically extending left-hand and right-hand side plates 12 and 13 spaced inwardly a slight distance from the respective ends of the base. Also mounted for rotation on the base 11 is a pressure roller 14 having its internal diameter in the center area thereof slightly larger than at the ends and tapering between the center area and the ends thus providing a crown roller configuration.

As shown in FIG. 3, which illustrates the one end of the drum 10 and the roller 14 and their supporting structure and which is similar to the other end, the drum and the pressure roller are confined and supported for rotation on three bearing rollers 15, 16 and 17 arranged at the apexes of an isosceles triangle, and a fourth roller bearing 18 rotatably supported on a pivot pin 19 and arranged for limited movement. The bearing rollers 15, 16 and 17 are arranged in similar fashion at both ends of the base 11 and are each rotatabl mounted by fixed pins 20 secured to and between the side plate 12 and an end plate 21 at the left end of the machine, as viewed in FIG. 2, and between the side plate 13 and an end plate 22 at the right-hand end. The fourth bearing roller 18 is mounted on a lever system and biased into engagement with the pressure roller 14. Further details of the roller and drum supporting arrangement will be described hereinafter in the description of the force generating mechanism for the roller 14.

In FIG. 4, the crown configuration of the pressure roller 14 is shown schematically in relation to the drum. The tapered diameter from the center area, which is relatively fiat toward the ends of the roller, as shown, are exaggerated in order to facilitate description. Good results have been attained from a configuration wherein each tapered end of the roller is approximately one-third of the length of the roller as is the center area, and the difference in diameter between the ends and the center area is one or two thousandths of an inch for a two-inch diameter roller.

In operation of the machine, during transfer there is a sheet of paper and a transfer sheet between the roller and the drum. Extremely high linear pressure or force will exist along the linear contact of the roller and the drum with the paper and the transfer sheet therebetween as transmitted by the supporting rollers 15, 16, 17 and 18. Because the paper and transfer sheet are compressible and also because the supporting rollers 15, 16, 17 and 18 are beyond the edges of the paper and the transfer sheet, the roller will be deflected; and if the pressure roller were of straight configuration instead of crown, the pressure at the ends of the linear contact would be greater than at the center. The effect of this condition would be the production of copies that were darker at the edge portions of the sheet and lighter in the middle area. In addition, this uneven pressure axially along the drum produces a component of force which runs axially inwardly along the linear contact, and this component of force will result in the sheet being processed becoming wrinkled and creased out of shape.

With the provision of a crowned configuration to the pressure roller, the deflection of the roller caused by the extremely high pressure is balanced by the beam strength of the roller thereby resulting in parallel linear surfaces for the linear contact and even pressures throughout the contact. With the presence of an even pressure, the transferred image will be even in contrast or density. In addition, the balanced or even pressure will eliminate the axially directed component of force which would have produced wrinkling of the sheet.

Within the drum there is mounted a drive motor 24 which is held in a fixed position externally by a plurality of screws 25 extending through the end plate 21. The diameter of the motor casing is slightly smaller than the internal diameter of the drum in order to provide sufficient clearance therebetween for the rotational movement of the drum. The drive shaft 26 for the motor extends through a suitable opening in the plate 21 and terminates in a pinion gear 27 secured thereto. (See FIG. 5) This gear meshes with an enlarged gear 28 rotatably mounted with a bearing 30 upon a screw 31 threaded into a flanged bushing 32 secured to the end plate 21. (See FIG. 6) A smaller gear 33 secured to the gear 28 and rotatably mounted on the bearing 30 meshes with a drive gear 34 for rotating the pressure roller 14.

As shown in FIG. 6, the drive gear 34 is secured by a screw 35 to a cylindrical thrust member 36 through which the screw slidably extends and which is slidably received into the left end of the roller 14. The member 36 is formed with an enlarge-d cylindrical portion 37 which engages the internal surface of the roller 14 and a reduced section 38 which extends out of the roller and through a suitable opening formed in the end Plate 21. The gear 34 is held against one end of the section 38 by the screw 35 which is threadedly received into a cylindrical hub clamp 39 also positioned within the roller 14 and engageable with the internal surface thereof. A sleeve 40 encircles a reduced section 41 formed inwardly of the thrust member 36 and also a reduced section of the clamp 39 which is spaced a slight distance from the extreme inward end of the member 36. The sleeve 40 engages the internal surface of the roller 14 and is positioned to engage at both ends O-rings 42 placed upon the respective reduced portions of the member 36 and the clamp 39. The screw 35, member 36, clamp 39 and the sleeve 40 are all in axial alignment with the roller 14.

As the screw 35 is tightened, the clamp 39 is drawn toward the member 36 on a pin 43 which prevents rotation thereby compressing the O-rings 42 against the internal surface of the roller 14 and also to secure the drive gear 34 against the outer end of the section 38. With this arrangement, as the gear train comprising the gears 27, 28, 33 and 34 is driven by the motor 24, the gear 34 will impart rotation to the roller 14 through the thrust member 36 and the O-rings 42. During rotation of the roller 14, the same is held against axial movement by the end plates 21 and 22 which are normally spaced a slight distance from thrust bearings 44 secured at each end of the roller.

As will be presently described, the drum 10 is driven for rotation by its frictional engagement with the pressure roller 14 which itself is driven by the motor 24. Neither the drum nor the pressure roller utilize a conventional shaft either for producing rotation or supporting the same. As previously stated, the drum and the pressure roller are supported for rotation by a set of bearing rollers located at each end of the machine, one set being located between the side plate 12 and the left end plate 21 and the other set being located between the side plate 13 and the right end plate 22. In order to accomplish these locations, each of the side plates 12 and 13 is formed with central enlarged cutouts 45, see FIG. 3, for the plate 12, in order to permit the extension of the drum 10 and roller 14 beyond these side plates.

One set of bearing rollers includes the three fixed rollers 15, 16 and 17 which are located at the apexes of an isosceles triangle having the axis of the rollers 15 and 16 located on the base of the triangular arrangement and one of the sides S extending between the axis of the roller 15 to the axis of the roller 17 while the other side S extends from the axis of the roller 16 to the axis of the roller 17. As shown in the schematic force diagram of FIG. 7, the axis A of the drum is located on the bisecting line B for the angle between the sides S and S The pressure roller 14, positioned between the drum 10 and the bearing roller 17, is held in this position by the roller 18 and has its axis A slightly offset with respect to the bisecting line B. The axis A is also slightly offset from a plane define by the axis A and a line of peripheral contact between the roller 17 and the pressure roller 14. With this arrangement, relatively great pressures on the order of to 300 lbs. per linear inch may be achieved at the line of contact between the drum surface and the surface of the pressure roller by the application of a relatively small generating force.

In order to accomplish this high linear force, each of the rollers 18 is mounted on a force producing lever 46 (see FIG. 3), which comprises two identical lever plates 47, 48 connected together and in spaced parallel relationship by suitable pins 50. Each lever 46 is pivotally mounted at one end by a pivot pin 51 between the plates 12 and 21 on the left side of the machine and the plates 13 and 22 on the right side. The roller 18 is supported for rotation between the lever plates 47, 48 on the pivot pin 19, which is located inwardly of the lever 46 from the pivot pin 51 therefor. At the other end of the lever 46 there is provided a spring biasing means comprising a coil spring 52 held in compression between a retaining cap 53 secured on the lever and a seat 54 secured to and between the plate-pairs 12, 21 and 13, 22.

As shown in FIG. 3, the spring 52 is adapted to rotate the lever 46 clockwise about the pin 51. This force is represented by the arrow F in the force diagram of FIG. 7. In this action, the roller 18 is continuously pressed against the pressure roller 14 which, as a result of this force, will react to wedge itself between the fixed roller 17 and the drum 10. The installation of these structural parts in such that the axis A for the pressure roller 14 is slightly displaced from the bisecting line B or, in effect, is offset relative to the plane defined by the axis A and the line of contact between the bearing roller 17 and the pressure roller 14 and thereby functions under the principles of toggle-joint mechanics wherein the resistance force opposing the movement of a toggle-joint connection by a given applied force is inversely proportional to the distance between theconnection and a line through the two points of resistance. The applied force illustrated by the arrow F in the arrangement diagrammed in FIG. 7 is the result of the force F produced by the compression of the spring 52 working across the movement arm measured from this spring force to the pivot pin 51. The effect of the force F is transmitted to the roller 18 as the force F and since the moment arm between the axis of this roller and the pivot pin 51 is relatively short, the transmitted or applied force F on the roller 18 is relatively great or many times greater than the force F In fact, the difference in the forces F and F is determined by the ratio of their effective moment arms, which, for the illustrated arrangement, is approximately 6 to 1.

The applied force F continuously produces a wedging action in the form of a component of the force applied radially of the pressure roller 14 thereby resulting in a force F between the contacting peripheries of the roller 14 and the drum 10. This force F is applied linearly along the drum and roller and parallel to their axes and is the result of the toggle-joint structural arrangement which produces a still greater force F than the applied force which in the illustrated case is the force F As previously stated, the resistance force in a toggle-joint arrangement, which in the present arrangement is represented by the force F is inversely proportional to the distance between the point at which the applied force or a component of the applied force is applied and the over-center point in the togglejoint. In the present arrangement, the former point is the axis A and the latter point is on the line B or on the plane defined by the axis A and the line of contact between the rollers 17 and 14. Since the distance between the axis A and the line B or the above-defined plane is very short, a relatively large resistance force F may be produced by arelatively small force F being applied radially of the pressure roller tending to bring the axis A into alignment with the plane. In effect, the wedging or toggle-joint action is produced by the arrangement wherein the distance between the roller 17 and the rollers 15, 16, which limit the radial outward movement of the drum and the pressure roller, is somewhat less than the sum of the diameters of the drum and pressure roller; and this component of force applied radially to the pressure roller attempts to toggle the drum-pressure roller combination through this slightly shorter distance.

For purposes of good pressure transfer, as will be presently described, the force F which is used for effecting transfer should be between 175 and 300 lbs. per linear inch. This relatively high force can be generated by a relatively lesser force F which, in turn, is produced by a still lesser force F Conversely, a relatively light force F is adapted to generate a relative high force F by means of the lever arrangement compressing the elements 18, 46, 51 and 52 and the toggle-joint mechanism comprising the elements 15, 16, 17 and 18 and 46.

From the foregoing it will be apparent that the linear force or pressure between the drum and the pressure roller 14 is accomplished with relatively little initiating force. It will also be appreciated that the copy drum 10 and the pressure producing roller 14 therefor are not mounted for rotation on shafts which would flex somewhat if subjected to the high pressures needed to effect pressure transfer. Instead, the drum and the pressure roller are mounted for rotation by the rollers 15-18 as well as each other in order to provide better and wider distribution of the great pressures which are necessary to effect good copy transfer.

Means are provided for guiding sheets of material such as transfer sheets, copy sheets and originals into, through and out of the machine. Other means are also provided to establish a relationship between the sheets for effecting programmed handling as the various sheets are conveyed through the machine and includes sheet registering devices and sheet clamping mechanisms.

In guiding sheets of material into the machine, a paper tray, generally indicated by the reference numeral 55, is provided and is arranged above the machine to direct a single sheet or double sheets to the vicinity of the nip of the drum-pressure roller arrangement. The tray is shown fully extended and in position to guide sheets into the machine; however, it may be retracted and pivoted from the position indicated by solid lines in FIG. 8 to the dotted position in order to eliminate the chance of damage when not in use and to blend into the contour of the machine.

The tray includes a guide plate 56 upon which sheets of material are adapted to rest when the leading edges thereof are in the nip of the drum-pressure roller arrangement. The guide plate has fixed thereto along both longitudinal edges a frame member 57 formed with longitudinal slots 58 into which the edges of the plate are fixed. The plate 56 may be extended outwardly by an extension plate 59 slidably received in slots 60 formed parallel to and above the slots 58. Magnet strips 61 secured to the top surface at the outer edge of the guide plate 56 and to the bottom surface, inner edge of the extension plate 59 serve to hold the plate 59 in its extended position when moved thereto. The magnet strips are arranged to intercept each other as the extension plate 5 is pulled out in order to limit the travel of this plate and are of sufiicient magnetic strength as to maintain the plates in an extended position until manually retracted wherein the strips 61 are forcibly detached for permitting movement or telescoping of the extension plate into the tray.

As shown in FIGS. 2 and 10, the forward edge of the guide plate 56 is secured as by welding to a support plate 62 which extends along the length of the machine and has at each end thereof a turned down ear 63 having slots 64 through which a rod 65 is adapted to project. The rod 65 extends longitudinally of the machine and its ends may terminate in suitable clearances recesses formed in the side plates 12, 13. The rod 65 is supported in a fixed position relative to the machine by a paper guide plate 66 having turned tabs 67 which encircle the rod near both ends thereof. The plate 66, in turn, is spot welded to a bracket plate 68 formed with bent extensions 69 at the ends thereof and which may be detachably secured to the machine casing, illustrated generally by the number 70, by suitable screws.

Between the rod holding tabs 67, the plate 66 is formed with an edge 71 which is utilized to hold the tray 55 in the angled elevational position shown in FIG. 8. This edge is adapted to be grasped by the forward edge of the guide plate 56 and the adjacent forward edge of the support plate 62, the latter edge being formed into a turned portion 72 spaced from the plate 62 a distance equal to the thickness of the edge 71.

In arranging the tray for paper supporting use, the same is pivoted about the rod 65 and pulled upward and to the rear of the machine at the same time in order to move the ears 63 until the rod 65 is at the lower ends of the slots 64. This will permit the bent portion 72 to clear the edge 71 of the plate 66. When shown in the position illustrated in FIG. 8, the tray 55 is gently pushed downwardly and forwardly of the machine in order to bring the edge 71 between the adjacent lower edge of the plate 56 and the turned portion 72 and firmly looked therebetween. The extension plate 59 may then be extended upwardly in order to provide a fully extended tray 55 for sheets of paper.

The bent extension 69 also supports an upper paper guide device 73 which cooperates with the lower paper guide plate 66 for guiding the transporting of various sheets of material into the machine. A normally open switch S-2 (see FIG. 10) connected to the motor 24 is mounted in the machine with its actuator in the input paper path so that the machine cannot be capable of operation without paper in the chute thereby preventing damage to the original sheet or master.

In emerging from the machine, the Sheets of material are guided by an upper stripper element 74 and a lower chute 75 (see FIGS. 8, 16 and 17). The stripper 74 is pivotally reained by outwardly projecting pins 76 to the machine casing and is formed along one longitudinal edge with at least two tongue portions 77 (see FIG. 2) which are preferably knife-edged in their outer extremities. A torsion spring 78 secured at one end to the machine casing 70 and at its outer end to the stripper serves to continuously force the knife-edged tongues 77 against the lower section of the pressure roller 14 on the output side of the nip for the drum-pressure roller combination. As a sheet or sheets of material are forced out by the rotation of the drum and the pressure roller, the sheet or sheets are prevented from adhering to the roller 14 and are stripped off this roller by the stripper 74.

The chute is spaced slightly lower than the stripper 74, as shown in FIG. 8, and includes an upper plow section 79 having a plurality of teeth 80 (see FIGS. 15 and 16) arranged along the outer edge thereof and spaced a slight predetermined distance from the periphery of the drum. This spacing is provided by end plates 79a (see FIG. 2) made integral with the chute 75 at the ends thereof beyond the edges of a sheet moving between the drum and the pressure roller. The plates 79a have Short and narrow bearing surfaces which conform to and contact the drum when the chute is in paper stripping position, as shown in FIG. 8. With the bearing plate against the drum, the teeth 80 will be spaced at predetermined distance from the drum surface.

The purpose for the spacing relative to the drum periphery is to provide sufficient clearance between the plow teeth 80 and the drum surface so that a master sheet can be supported on the drum without danger of interference or damage to the master caused by the plow teeth.

The chute 75, the end plates 79a and the teeth 80 are movably mounted relative to the periphery of the drum by being secured to the front cover 70 which itself is pivotally mounted on the machine base by suitable pivot pins 80a secured to the casing and rotatably supported in the end plates 12, 13 As shown in FIG. 5, the casing 70 may be swung outwardly about the axis line defined by the pins 80a at each end of the machine.

The chufe 75 is adapted to be held at this predetermined distance from the drum periphery and is made movable relative thereto by the use of two sliding wedge blocks 81, each of which is adapted to be driven manually by a thumb tab 81a through a suitable opening 81b formed in the chute 75 and through an aligned square opening having a straight bearing edge 81c formed in the machine casing, such as the plates 12, 13. The wedging taper of the blocks 81 will, when driven, slide along each of the straight edges 810 for pressing the end plates 79a against the drum and drawing the chute '75 snugly into a secure position upon the machine base wherein the edges of the teeth 80 are spaced the predetermined distance from the periphery of the drum. This pressure against the drum and the drawing of the chute will cooperate with the pivot pins 89a for providing a rigidsupport for the front casing 70 and the chute 75. When it is desired to replace the chute or to move it away from the drum for clearing the drum of paper jams or permit cleaning of the drum, the blocks 8 may be pulled toward each other for permitting detachment from the openings and the machine. The casing 70 may then be swung outwardly and upwardly to expose the drum and pressure roller. Repositioning of the casing 70' and the blocks 81, as previously described,

will again return the teeth 80' precisely to their previously occupied positions relative to the drum.

Because of the critical predetermined spacing between the drum periphery and the adjacent portions of the teeth 80, it is important that the teeth be returned to a precise positioning each time the casing 70 is moved. This is accomplished by the pins 80a which insure that the forward edges of the teeth will be positioned parallel to the axis of the drum, and by the bearing surface on the plates 79a and the wedging of the blocks 81 which insure that the spacing between the teeth and the drum periphery will be uniform throughout the length of the drum and will be the same as the previous positioning of the chute 75. In effect, then, the blocks and the cooperating structure insure that the chute 75 will automatically become aligned for each use of the blocks and cooperating structure,

As previously indicated, the machine is provided with means for establishing positionable and operative relationships between the sheets which are introduced into the machine in order to effect programmed handling of the machine operation. These means include sheet registration devices and clamping devices as well as various operative mechanisms associated therewith.

Before commencing the description and operation of these devices, a brief outline of the sheet manipulation that occurs during a complete machine cycle of operation will now be made. During the first stage of operation of the machine, both a blank transfer sheet and an original which has been typed or otherwise imprinted with an appropriate ink formulation, which will readily transfer from one sheet to another by the application of extreme pressures, are inserted preferably simultaneously into the nip of the drum-pressure roller combination. It is imperative in this step that the transfer sheet be applied so that it will be in contact with the drum 10 during rotation thereof and that the type script to be copied be in contact with the transfer sheet. Both the transfer sheet and the original are driven through the nip of the drum-pressure roller and during the drive, which in this stage will be a single revolution of the drum, the transfer sheet will become clamped to the drum and remain so while the original is immediately stripped and directed out of the machine by means of the guide '74 and the chute 75.

The next step in the cycle of operation requires the insertion of individual sheets of copy paper into the machine. During this step, the image on the transfer sheet is transferred to each copy sheet as they are inserted individually in the machine. During each transfer, the transfer sheet remains on the drum, and the copy sheet is stripped out of the machine until the last programmed copy sheet has been made. As the last copy sheet is being stripped out, the transfer sheet is also being removed from the machine so that both sheets more or less are removed simultaneously.

For automatically controlling positioning of the original sheet of material from which a transfer sheet will derive its inked image and for the automatic positioning of subsequently applied sheets of copy paper, the drum is provided with a plurality of registration devices 82 each having a pin 83 against which the leading edges of copy sheets or the original sheet abuts and which are arranged in a line parallel to the axis of the drum but coincident with the periphery thereof. As shown in FIGS. 11 and 12, the pin 83 extends radially of the drum beyond the periphery thereof and is formed with an enlarged diameter section 84 having an annular shoulder 85. The registration device 82 is adapted to slide within an inverted cylindrical element 86 tightly fitted into an opening 87 formed in alignment in the wall of the drum 10. A spring 88 normally held in compression within the element 86 between the bottom closed wall thereof and an inner wall of the shoulder 85 thereby normally biases the registration pin 83 outwardly and the shoulder 85 slightly beyond the periphery of the drum surface. In order to maintain the pin 83 and the section 84 within the cylindrical element 88, the pin S3 extends within the element 86, through the opening in the bottom wall thereof and terminates in a split and flared end 89 which prevents extraction of the pin 83 from the device 82.

As shown in FIGS. 15, 16 and 17, the registration pins 83 are adapted to engage a sheet of material, such as copy paper or an original, indicated by the reference letter P. As shown, the sheet P, when laid upon the paper tray 55 or when shoved toward the nip of the drumpressure roller combination, is prevented from assuming any other position except that shown in FIGS. 15 and 16. The illustrated positions are those assumed by the original P and the transfer sheet just prior to initial operation of a production cycle. The forward edge of the sheet P is shown in engagement with the pins 83 which are held slightly downwardly by the trailing edge of the paper guide 73. This engagement of the pins 83 with the lower surfaces of the upper guide 73 insures that the leading edge of a paper sheet will not go above or beyond the registration devices when the paper is inserted into the machine. Lowering of the pins 83 also maintains the shoulders 85 below the periphery surface of the drum and out of the way when sheets of paper are introduced into the machine thus insuring that an original document or copy sheet is always against the registration pins 83 just prior to start of machine operation. In addition, by maintaining the pin 83 and shoulder 85 in a lowered position prior to start of operation also minimizes the chances that the edge of a sheet of material will be turned down toward the drum periphery by the friction produced by the pins 83 as they are completely lowered by the roller 14 during machine operation. Normally, the leading edge of a sheet of paper is held above the periphery of the drum by the shoulder 85, as shown in FIG. 17, and which will be discussed hereinafter. A groove 6 is formed in the lower surface of the guide 73 for each of the registration pins and prevents the leading edge of the sheet P from being placed above the pin 83 or to come between the top of the pin and the lower edge of the guide 73. As previously stated, the sheets P and T, when introduced into the machine, assume the initial position shown in FIG. 16 where the edge of the sheet P is against the pins 83.

The drum is also provided with a plurality of clamping devices which serve to selectively clamp a transfer sheet, designated by the letter T, to the drum periphery.

These clamping devices, designated generally by the reference numeral 90, are spaced alternately with the registration devices 82 and are arranged along a line parallel to those devices but spaced slightly forward therefrom. As shown in FIG. 15, the transfer sheet T is formed with a scalloped forward edge having extension tabs 91 which are each applied to one of the clamping devices. Since there are four extension tabs 91, then only four clamping devices will be necessary. It will also be seen in FIG. 15, that the clamping devices 90 and the registration devices are arranged such that the tabs of the scalloped edge of the transfer sheet T leads, or is forward of the leading edge of the copy sheet P.

The details of one of the clamping devices are shown in FIGS. 13 and 14. Each device includes a moulded plastic block 92 adapted to extend through a suitable circular opening 93 formed in the wall of the drum 10. A pair of parallel arranged mounting rods 94 extending through each of the blocks and along the entire length of the drum (see FIG. 6) serve to hold each of the blocks in proper position within their respective openings 93. These rods are mounted in and between bearing bushings 95 which are held into the ends of the drum by these rods and a third tie rod 96 located diametrically of the rods 94. Suitable screws 97 may be utilized to fasten the ends of the rods to their respective bushings 95.

Each block 92 is formed with a lower enlarged section 98 which is contained within the interior of the drum 10 and through which the mounting rods 94 project. Formed integrally with the lower section 98 is an upper reduced section 100 which fits within the opening 93 and terminates in an upper surface 101 slightly below the plane of the upper end of the opening 93. From FIG. 13, it will be seen that the section 100 is curved at its forward and rearward ends to fit snugly into the oppositely curved sides of the opening 93 thereby precisely locating each of the clamping blocks and maintaining these in a fixed position against forces which will act along circumferentially of the drum.

Both the sections 98 and 100 of each block are formed with a continuous central recess 102 which, when traced radially of the drum, is opened at the bottom of the section 98 and closed at a point within the upper section 100 slightly below the top surface 101. When traced axially of the drum, the recess 102 extends completely through or, in other words, is open at both sides of the block 92. However, the recess, when traced axially, is partially closed by the metallic side plates 103, 104, one located on each side of the upper section 100 of a clamping element that is movably mounted upon the block 92. This clamping element, generally indicated by the reference numeral 105, includes the parallel arranged side plates 103, 104 which are formed with upper edges 106, 107, respectively, that are inclined upwardly toward the rear of the block 92, a rear plate 108 integral therewith and with an extension tab 110 of the rear plate. The tab extends above the side plates 103, 104 and the rear plate 108 and is bent toward the forward end of the block 92 at a point slightly above the highest inclined point relative to the upper edges 106, 107. In order to accommodate the rear plate 108, the upper section 100 for the block 92 is formed with a slot 111 into which the plate 108 may slide radially relative to the drum 10. Preferably, the clamping element 105 is formed from a single piece of stamped spring metal, thereby permitting limited flexing of the tab 110 during operation of the clamping device.

The clamping element 105 is adapted for vertical movement, as seen in FIG. 14, or radially relative to the drum axis in order to accomplish clamping and unclamping of the scalloped leading edge of the transfer sheet T. In the position shown in solid lines in FIG. 14, the tab 110 engages the top surface 101 of the block 92 and is normally held in this position by a spring 112 held in compression within the rec ss 102. This spring at one end engages the upper wall of the section and at its other end is forced against a pin 113 which extends through the side plates 103, 104 and the recess. When in clamping position, one of the tongues 91 of a transfer sheet is adapted to be held between the tab 110 and the top surface 101. The purpose of the inclined upper edges 106, 107 is to guide the leading edges of the tabs 91 fully into the space between these edges and the clamping tab 110 in order to insure full aligned gripping of all of the tabs 91. In addition, the incline to the upper edges permits the raising of the leading edges of the tabs 91 above the surface of the drum during stripping of the transfer sheet.

Means are provided to release each of the clamping devices simultaneously, and to this end the drum has mounted internally therein and parallel to its axis a release rod 114 which is adapted to be inserted in the recess 102 in each of the clamping block positions 98. As shown in FIGS. 6 and 14, the rod 114 is arranged between the tie rods 94, is rotatably retained at one end of the drum and extends out the other end thereof terminating in a cam actuator element 115 secured to the end of the rod. The rod is formed throughout its length or at least in that portion immediately below each clamping device 90 with a fiat cam surface 116 upon which the lower edges 117 of the side plates 103, 104 for each clamping element are forced by their respective springs 112. Normally, the rod 114 is held by its own mounting means in the position shown in FIGS. 14 and 18 wherein all of the clamping tabs are held down against the top surfaces 101 of the clamping blocks. In order to effect this condition, the cam surface 116 must be parallel with the bottom edges 117 in order to present the latter with the longest possible distance they can travel.

For release of the transfer paper or to maintain the clamping devices in unclamped positions prior to the insertion of a transfer sheet into the machine, as will be described below, the release rod 114 is rotated in order to cam the edges 117 upwardly thereby forcing each of the clamping elements 105 upwardly against the bias of their respective springs 112. This rotation of the rod will simultaneously release all of the clamping devices 90. Release of the rod to assume its normal position, that is, removal of any force which will cause rotation, will permit a spring 118 (see FIG. 6) which encircles the release rod 114 to return the same to its original position against a stop (not shown). In order to eliminate any restrictive force upon the extension tabs 110 when the same are fully opened at the end of a production run, as shown in FIG. 16, the paper guide 73 is formed with grooves similar to but deeper than the grooves G for permitting total clearance for the tabs 110.

The reproduction machine is provided with a programming mechanism which controls the operation of the machine once it is set in motion and in cooperation with a copy counting mechanism and an electrical control circuit. The programming mechanism, illustrated in operative detail in FIGS. 19 through 24, is located in the machine between the end plate 22 to which it is attached and the machine casing, see FIG. 2. Generally indicated by the reference numeral 120, the programmer comprises a number of control levers which assume various motions and positions duringa single and complete reproduction cycle. Such a cycle requires two complete rotations of the drum 10, one to convert the master or transfer sheet T into a master and one revolution to produce one copy from the transfer sheet. The structure of the programmer mechanism and the counter mechanism is such that every reproduced copy desired requires one full rotation of the drum. For any series or multiple copy program, there will be as many drum rotations as there are programmed copies to be made plus one additional rotation to produce the master transfer sheet.

The programmer mechanism 120 comprises a first lever 121 pivotally mounted on and arranged parallel to the plate 22 by a pin 122. It is preferred that the lever 121 be spaced from this plate by an integral boss 123 in order to provide space between the lever and the plate 22 for additional structure. A torsion spring 124 is anchored at one end on the pin 122 and the lever 121 and normally biases the lever counterclockwise, as viewed in FIG. 19, toward a stop 125 secured to the plate 22. However, other structure normally limits this rotation of the lever, as will be presently described.

counterclockwise rotation of the lever 121 is prevented by the intervention of two individually controlled actuating members which need release in order to allow further rotation of the lever. One of the actuating members is in the form of a cam lobe 127 positionable in the path of a cam surface 128 of the lever and which is integral with and radially protrudes from a circular element 129 having a circular ratchet 130 formed thereon together with a copy indicating and setting knob 132. The element 129, ratchet 130 and the knob 132 are rotatably fastened to the plate 22 by a screw 131.

The other actuating member which releasably impedes rotation of the lever 121 is a latch element 133 normally within a recess 134 formed in the free end of the lever. The latch 133 is integral with a boss 135 secured to a shaft 136 to be rotatable therewith. The shaft 136 is mounted for limited rocking or rotation within suitable apertures formed in the machine side plates 12, 13 and has secured thereto a push bar 137 accessible from the exterior of the machine to permit actuation by a machine operator. Manual depressing of the push bar 137 will produce counterclockwise rocking of the shaft 136, as viewed in FIG. 19, with consequent movement of the latch element 133 out of the recess 134.

A torsion spring 138 having one end anchored in the plate 22 and its other end fastened to the boss 135 serves to normally maintain the push bar 137 in its uppermost position, the one illustrated in FIG. 19, once it has been actuated. The latch 133 is formed with a thin narrow cross-section which ofiers some limited resiliency to the element. When the bar 137 is rotated back to its initial position by the spring 138 and after the operator has released the bar, the latch element will remain out of the recess 134 and against the upper end of the lever 121 under its own resilient force. When the lever is rotated clockwise, the element will snap back into the recess 134 when in alignment therewith.

The programmer mechanism 120 is provided with a second lever 140 made integral with the boss 135 and therefore pivotally mounted with the shaft 136. As shown in FIG. 20, the lever 140 is in a plane parallel with the plane of the lever 121 and very close thereto and is provided with a cam surface 141 cooperable with the cam lobe 127 in the same manner as the surface 128. However, the lever 140 is also provided with a second cam surface 142 adjacent the surface 141 and angled therefrom by approximately 90. This cam surface extends horizontally above the lobe 127 and is normally biased in this position in contact with the upper tip of the lobe by the torsion spring 138 which acts upon the shaft 136 and the boss 135. The lobe 127, in effect, prevents rotation of the lever 140 when the machine is in shutdown condition, as shown in FIG. 19.

A third lever 144 is also provided in the mechanism 120, and this lever is pivoted at its upper end by a pin 145 secured to the plate 22. A torsion spring 146 having one end secured to the plate 22 and its other end secured to the lever 144 normally biases the same in a counterclockwise direction. The lever 144 is in a plane parallel with the planes of the levers 121 and 140 and is spaced inwardly therefrom toward the plate 22. Pivotally mounted by a pivot pin 147 on the lever 144 in a plane parallel thereto and spaced therefrom toward the lever 121 is a latching lever 148. A torsion spring 150 normally biases the projecting end 152 of lever 148 in a clockwise direction and against a latch stop 151 formed on the lever 121.

The programmer mechanism 120 is also arranged to cooperate with three switches which may be suitably mounted on the end plate 22 at levels which will permit actuation by the levers previously described. The conditions and function of these switches will be discussed hereinafter during the description of the operation and the electrical system. However, their cooperation with the levers will be briefly stated at this point in order to better illustrate the sequences of events that the programmer experiences.

One of the switches, S1, the push bar or the start switch is provided with a switch actuator 153 cooperable with a tab 154 formed on the lever 140. The second of the switches, the home switch 'S3, is provided with a switch actuator 155 cooperable with a boss 156 formed on the cam actuator 115. The third of the switches, the master count switch 5-4, is provided with a switch actuator 157 made cooperable with a cam edge 158 formed on the middle section of the lever 121 to be actuated thereby when this lever is pivoted from the position shown in FIG. 19 to the one shown in FIG. 21.

To set the programmer 120 and, consequently, the machine in operation, the operator must perform two actions after sheets of material have been inserted into the machine. When not in use and at the close of a previous operation of the machine, the programmer and its control structure are in the positions shown in FIG. 19. The first step or action to be performed is to dial the number of copies to be produced on the machine, and to this end the operator rot-ates the knob 132. until a selected number from the numerals 160 is in registry with suitable indicia or reference point on the machine casing. For purposes of the present description, it will be assumed that the knob 132 has been rotated to effect the production of three copies. In FIG. 21, the ratchet 130 has been rotated counterclockwise in the direction of the arrow to effect this selection of copies to be made. A spring clip 161 (see FIG. 19) engagea'ble with the individual teeth of the ratchet will releasably hold the ratchet into any position it is rotated.

In rotating to the position shown in FIG. 21, the cam lobe 127 was'also moved to thereby release its engagement with the cam surfaces 128 and 142. As previously stated, the clamping shaft 114 is normally biased to a predetermined position by the return spring 118, and this position is one wherein the program control actuator and a cam 163 formed thereon assume the position they take in FIG. 21. Such a biasing action by the spring 118 also results in the closing of the clamping devices 90. However, in order to condition the machine for ease of operation and to render it accessible for more immediate use, the shaft 114 is normally held in a second predetermined position to maintain the clamping devices 98 open when the machine is in ready-touse condition. In this condition, sheets of paper may be inserted into the machine which is disposed to clamp the transfer sheets T along the scalloped edge thereof. The second predetermined position of the Shaft 114 is maintained by the engagement of the cam 163 against a cam surface 164 formed on the lever 121, as shown in FIG. 19. This will maintain the clamping tabs 110 in their unclamped positions when the machine is standing idle, as shown in FIG. 16.

The second operative step to be performed by the operator is to depress the touch bar 137 momentarily. This action will cause the upward movement of the latch element 133 in order to free the lever 121 for counter clockwise rotation. Since the cam lobe 127 was previously moved out of the path of movement of the cam edge 128, the lever 121 is now totally free to rotate 

